Shockproof electrical device and a shock absorbing and distributing means therefor



July 2-8, 1936.

A. c. BLAKEMAN 2,049,287 SHOCKPROOF ELECTRICAL DEVICE AND A SHOCK ABSORBING AND DISTRIBUTING MEANS THEREFOR Filed Sept. 2, 1931 INVENTOR f i fiCBL/I/(E/WM/ ATTOR Patented July 28, 1936 PATENT OFFICE SHOCKPROOF ELECTRICAL DEVICE AND A SHOCK ABSORBING AND DISTRIBUTING MEANS THEREFOR Arthur C. Blakeman, North Arlington, N. 1., assignor to Westinghouse Lamp Company, a corporation of Pennsylvania Application September 2, 1931, Serial No. 560,738

5 Claims.

This invention relates to electrical devices and more particularly to tubes of this character having relatively heavy electrodes or other elements generally supported by, located within and spaced from the interior walls of a readily frangible envelope and/or sleeve, as for example, X-ray or other tubes especially adapted for general radiographic purposes;

1 In order that the description of my invention may be clear and concise and so that its advantages may be readily apparent, I will describe 7 my invention in conjunction with an X-ray tube.

One form of X-ray tube comprises a cylindrical glass envelope having one of its ends of a bulbous or hemispherical contour and having at the other end a reentrant tube whose diameter is substantially less than the corresponding dimension of the envelope. Along about the middle third length of the envelope is a second reentrant tube, with one of its ends firmly secured to the envelope. Disposed above the free end of the second reentrant tube is a suspended metallic screen housing a cathode and having its outer surface spaced from the inner wall ofthe envelope. The inner end of the first mentioned reentrant tube has firmly sealed thereto a metallic' sleeve adapted to support an anode which passes therethrough. The anode, being of such lengthwise dimension that its free loaded end is spaced from and within the inner side walls of the metallic screen, has the outer periphery of a substantial portion thereof surrounded by and spaced from the inner wall of the second reentrant tube.

Heretofore the general deficiencies in the physical characteristics in tubes of this character have been appreciated and to some extent eliminated by Ulrey and Ehrke in the manner defined by them in their United States Patent No. 40 1,715,152 issued May 28, 1929.

Broadly, the means therein described for improving the physical characteristics of a tube of this character consists of a slotted cylindrical resilient means for supporting the anode and 45 metallic screen from the side walls of the reentrant tube and the envelope, respectively. This resilient means consists essentially of a collar or sleeve adapted to fit closely around the member to be supported and further characterized by an 50 outwardly and downwardly extending shoulder integral therewith, and a slotted extended cylinder depending from said shoulder. This resilient means is fixedly secured to the member to be supported by means of stud bolts.

Although this particular means has greatly improved the physical characteristics of these tubes so as to make them more rugged, their manufacture is a costly operation. Moreover, when employing a cylindrical resilient means of this character it is necessary that the outer circumferential dimension of the extended slotted cylindrical portion closely approximate the interior circumferential dimension of that member with which it is to be in frictional contact, otherwise there are a number of line, rather than surface, contacts between the resilient means and the frictional supporting members which is obviously undesirable because of the danger of cracking the supporting member along these lines of contact upon a jarring or shocking of the tube.

As a specific improvement thereover this invention has a number of advantages which will be readily apparent from the description and drawing.

An object of my invention is to provide a rugged electrical tube including a frictional bearing element which may be readily manufactured at a low cost, and may be readily assembled and reclaimed.

Another object of my invention is to provide a resilient means of such construction that it may afford a comparatively large surface contact with a frangible elementof an electrical tube.

A further object of my invention is to provide a resilient means adapted to serve as a friction bearing element in an electrical tube in order to render the same more rugged and of such a character that its resiliency is not adversely effected by high temperatures.

In the drawing:

Figure 1 represents a sectional view of an X-ray tube embodying my invention;

Figure 2 represents a sectional view taken along line II-II of Figure l.

Figure 3 represents a perspective view, with a cross sectional illustration of my improved resilient supporting and shock distributing means embodied in the upper end of an X-ray tube;

Figure 4 represents a sectional view taken along lines IV-IV of Figure 1; and- Figure 5 represents a perspective view, with a cross sectional illustration of my improved resilient supporting and shock distributing means embodied in one of the reentrant tubes of an X-ray tube.

As shown in Figure 1, the X-ray tube may comprise a transparent, gas tight, cylindrical glass envelope 10, of bulbous or hemispherical contour at one end II, and having a reentrant tube l2 at its other end. Located above the re- 55 house a cathode asat I5. The

. the commercial 7 metallic screen.

7 means are of such a composition entrant tube |2 and. firmly secured to the envelope I I] is a second reentrant tube |3 of substantial length. Above the free end of the second reentrant tube 3 is a nickel-iron screen l4 serving to screen out undesirable X-rays and to V cathode within the housing is supplied with electrical current by means'of the conductors I6 hermetically sealed to the glass envelope and serving to support the The inner end of the reentrant tube l2 has firmly sealed thereto a metallic sleeve which supports an anode, I8 This anode I8 extends upwardly in the tube with a substantial portion of its outer surface spaced from and surrounded by the reentrant tube l3, and with its loaded end 19 spaced from and within the metallic sleeve l4.

According to my invention, in order that a tube of this character may be able to withstand shocks without any danger of breaking during manipulation, transportation and operation thereof, I provide therefor my n oyel type of resilient means 20 and 2| which are adapted to be employed therewith as ashock' distributing and absorbing means. Besides hav- 7 ing the above characteristics I prefer that said that they do not lose their resiliency during the heat treatture. j V i I For this purpose, the resilient members 20 and 2| are preferably made of resilient molybdenum metal or the like which worked to any desired shape. ments 20. and 2| are in the form of a plate of may be mechanically V substantiallyfiat or slightly curved contour, with a pair of spaced nipples 22 The edges of each plate are preferably rounded V and two of the oppositely disposed relatively wide member, all being clearly itss'urroundin'g member, a

mar a r e 9 th plates a d a preferably curved inwardly so that upon assembly a comparatively large surface frictional contact between 'the' plate and its surrounding member maybe obtained so astc'feliminate all sharp line contacts between the edges of the plate and d so that the round-, be in close proximity with the surrounded illustrated in Figures ed edges of the plate may and preferably v in contac t 2-4 inclusive. 7 f V 7 iInifurther accordance with my invention, the metalliese'reen l4 and that portion of the anode I8 surrouh ddby tube' respectively, have on their outer peripheries a plurality of one hundred and twenty degrees spaced rows of depressions 25 and 26 respectiv'e'ly, with the depressions of each ;of the respective rows spaced from each other a distance equal to'the distance between the nipples of the. respective plates 20 and 2|. These depressions may be readily formed in these meme bers by means of a simple drilling operation :and are of such dimensions as to be equal to or slightly greater. than the dimensions of the nipples, so 7 that when'mounted, the nipples will fit snugly therein. 7

As shown, there are three spaced plates 20 and three spaced plates 2| "mounted respectively between the metallic screen M and the envelope a l'uandbetween the anode l8 and the reentrant tube 3 and around the screen l4 and the anode and 23, fitting snuglyjin 6, with the plates ,fiexed IS, with the nipples 22 the depressions 25 and e 2 inwardly towards the'surrounded members and' e eeai rpoaip f t e eli e? was:

element, such as the anode, of the tube in the course of its I nan ufac- The resilient ele and 23 respectively.

the envelope and the reentr'ant walls of the envelope l3 respectively, the marginal portionsof these plates contacting: the metallic screen l4 and the anode |8 respec- 'tively.

With the above construction, it is "apparent that there are substantially no line contacts berounding elements l0 and 3, but there'is a substantially large surface contact between these plates and their surrounding elements and fur: ther, that there are a plurality of spaced firm contacts between the surrounded elements I4 I and 8 and the plates.

Moreover this. constructhe plates 20 and 2| bearing against the inner l0 and the reentrant tube and with the rounded ends -'of V tween the bearing plates 20 and 2|, and the sur- '7 tion eliminates the necessity of forming. threads on the element to be supported and eliminates between the plates and the'surrounding member, provides a relatively soft 7 V or; even frictional contact which serves to maintain thesurrounded I8 or screen; M inposition and allows the anode and screen to creep due to temperature changes, and still further, these-plates can be efficientlyemployed with ing elements frequently found to bejdut 5 surround of round;

7' These plates 20,and 2|, thethiekness of which may vary, and I have found that plates of this character measuring .012 inch in thickness serving my purposein X-ray tubes, may be readily and economically manufactured. 'One' of :the me h ds eh I a e .e ye i s. rpos consists ve ine a Sh e of molyb n m m tal into blanks of appropriatesizeythereafter sub- J t ne the lanksto a orminepp a o as tween Imale and female diesjof appropriate con; t u s whe b to, p o e -s a gener c tour of the blank and to form the nipples therein.

T e d e theso formed p a sma em n ed' oifif desired and the plates maybe finally subi ctedt i run through an elevated temperature reducing t o pher q .lhe thusiinished latesare, of course. readily interchangeable and may be readilyassembled in suitable cleaning treatment, such asa an X-ray tube in any conven ent manner. ".Be-

sides being interchangeable, these plates have an:- he advanta o be e il .r slaimed.

Ithas been found that Xeray tubes embodying myinvention as before described maybe readily n in xpen ive manufactured to provide .arugged tube which will withstand shocks; and

jarring without cracking of the frangible embe s H i ut ned y invention is apparent' that there may be many variations, of; the same without essentially departing from the nature and scope thereof asfis set forth' in the following claims: 7

Whatis claimed is:

ing a longitudinal marginal portion curved inwardly and away from said frangible member, with the longitudinal edge of said marginal portion being located inwardly and away from said frangible member and adjacent said other member, at least one of said resilient means being flexed around said other member and having the major portion of one of its surfaces bearing against a surface of the frangible member and its opposite surface bearing against a surface of said other member.

2.. An electrical device comprising an evacuated envelope, a plurality of electrodes therein, a readily frangible member surrounding and spaced from the outer periphery of one of said electrodes, and a plurality of individual and separate spaced resilient plates between said electrode and said member with each of said plates bearing against said electrode, flexed therearound and having the major portion of one of its surfaces in frictional contact with said member, said plates having their longitudinal edges located inwardly and away from said member.

3. An electrical device comprising a cathode, a member surrounding the cathode of said device, a plurality of heavy elements disposed therein, with one of said elements spaced from and surrounded by said surrounding member, said surrounding member being frangible, and a plurality of separate and individual spaced resilient plates mounted around said element and between said element and said frangible surrounding member, each of said resilient plates having portions thereof curved inwardly towards said element, with the longitudinaledges of said plates being located out of contact with and away from said frangible member, the major portion of one surface of said plate being in frictional contact with said frangible member, the opposite surface of said plate being in contact with said element.

4. An electrical device comprising a cathode, a readily frangible member and a plurality of heavy elements disposed within and spaced from the inner periphery of said frangible member, a plurality of depressions in the outer periphery of one of said elements, a plurality of resilient plates having means adapted to lie in said depressions, said plates located between said element and said readily frangible member, said plates having the major portions of the outer surfaces thereof in frictional contact with said frangible member, the inner surfaces of said plates contacting said element, said plates being flexed around said element, with the longitudinal edges being located away from and out of contact with said frangible member.

5. In an X-ray tube, a readily frangible envelope having a plurality of relatively heavy elements spaced from and located within said envelope, a cathode within said envelope, one of said elements having a plurality of depressions on the outer surface thereof, a plurality of individual resilient plates located between said element and said envelope, means on said plates located in said depressions, said plates being flexed around said element and having the major portion of the outer surface thereof in frictional contact with said envelope, with the edges of said plates extending longitudinally of the envelope and being out of contact with and located inwardly from said envelope.

ARTHUR C. BLAKEMAN. 

